I recently used homeplugs to transfer the internet from one part of a friends house to another and it worked very well.
I have another friend who is considering using them, but his house is slightly different. The house is long and thin with very thick walls and the master socket is in the middle.
The home plugs I bought were a pair, though I noticed that they were also sold singly. Am I right in thinking that he could use three. One connected to the router in the middle and one at each end of the house? The ones I bought were Solwise ones through homeplugs.co.uk.